// stores the reference to the XMLHttpRequest object
var xmlHttp = createXmlHttpRequestObject(); 

// retrieves the XMLHttpRequest object
function createXmlHttpRequestObject()
{	
  // will store the reference to the XMLHttpRequest object
  var xmlHttp;
  // if running Internet Explorer
  if(window.ActiveXObject)
  {
    try
    {
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    catch (e) 
    {
      xmlHttp = false;
    }
  }
  // if running Mozilla or other browsers
  else
  {
    try 
    {
      xmlHttp = new XMLHttpRequest();
    }
    catch (e) 
    {
      xmlHttp = false;
    }
  }
  // return the created object or display an error message
  if (!xmlHttp)
 
    alert("Error creating the XMLHttpRequest object.");
  else 
    return xmlHttp;
}

// make asynchronous HTTP request using the XMLHttpRequest object 
function process(param,value)
{
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  { 
    //alert(param+"="+value);
    if (value=="1000000")
    {
        xmlHttp.open("POST", "start.php", true);
        xmlHttp.setRequestHeader("Content-Type", 
                                   "application/x-www-form-urlencoded");
        xmlHttp.onreadystatechange = handleServerResponse;
        xmlHttp.send(param+value);
        //alert("y");
    }
    else
    {
      xmlHttp.open("GET", "start.php?"+param+"="+value, true); 
      // define the method to handle server responses
      xmlHttp.onreadystatechange = handleServerResponse;
      // make the server request
      xmlHttp.send(null);
      //alert(param+"="+value);
    }
  }
  else

    // if the connection is busy, try again after one second  
    setTimeout('process('+param+',value)', 1000);
}

// executed automatically when a message is received from the server
function handleServerResponse() 
{
  // move forward only if the transaction has completed
  if (xmlHttp.readyState == 4) 
  {
    // status of 200 indicates the transaction completed successfully
    if (xmlHttp.status == 200) 
    {
      // extract the XML retrieved from the server
      //xmlResponse = xmlHttp.responseXML;
      // obtain the document element (the root element) of the XML structure
      //xmlDocumentElement = xmlResponse.documentElement;
      // get the text message, which is in the first child of
      // the the document element
      //helloMessage = xmlDocumentElement.firstChild.data;
      // update the client display using the data received from the server

      var response = xmlHttp.responseText;
      // server error?
      if (response.indexOf("ERRNO") >= 0
      || response.indexOf("error:") >= 0
      || response.length == 0)
      throw(response.length == 0 ? "Void server response." : response);
      // retrieve the document element
      response = xmlHttp.responseXML.documentElement;
      // retrieve the flag that says if the chat window has been cleared or not
      sel = response.getElementsByTagName("sel").item(0).firstChild.data;
      menu1 = response.getElementsByTagName("menu").item(0).firstChild.data;
      content1 = response.getElementsByTagName("content").item(0).firstChild.data;
      //mykeys = response.getElementsByTagName("key").item(0).firstChild.data;
      //oblogka = response.getElementsByTagName("oblogka").item(0).firstChild.data;
      //number = response.getElementsByTagName("number").item(0).firstChild.data;

      document.getElementById("title").innerHTML = sel;
      document.getElementById("scrollable1").innerHTML = menu1;
      document.getElementById("content").innerHTML = content1;

      // restart sequence
      //setTimeout('process()', 1000);
    } 
    // a HTTP status different than 200 signals an error
    else 
    {
      alert("There was a problem accessing the server: " + xmlHttp.statusText);
    }
  }
}